In a widely used form of sliding door used for closets and other fairly light-duty applications, the door is formed by a relatively thin panel of hardboard or similar material, with a suitable decorative facing, or by a mirror, to the edges of which are applied metallic stiles and rails linked by top and bottom corner connectors which also support and guide the door for sliding movement along top and bottom tracks fixed in a door opening. The top connectors have upwardly projecting arms carrying rollers which suspend the door from the upper rail, whilst the bottom connectors have downwardly projecting arms terminating in guide members which engage the lower rail and maintain the door in the desired plane whilst accommodating some degree of irregularity in the vertical spacing of the top and bottom tracks.
Progressively improved versions of such corner connectors are described in detail in Canadian Pat. Nos. 660,588 (Brydoff), 744,178 (Brydoff et al) and 844,876 (Kellems). The structures of the last of these patents not only links the stiles and rails, but also draws them together during assembly and largely eliminates the need for screws, rivets or other separate fastenings to secure the parts together.
Whilst the connector of the Kellems Canadian Pat. No. 844,876 has a number of advantages and performs very satisfactorily in many respects, I have sought to produce a connector which whilst retaining these advantages is simpler and cheaper in construction, and which avoids the causes of certain manufacturing and assembly problems which have arisen in practice with the prior art connector.
As is apparent from the Kellems patent, a single door panel requires four different corner connectors. It would clearly be an advantage to reduce this number of different parts.
Although the arms of the bottom connectors can be retracted for transportation of an assembled door, this is not the case for the suspension arms of the upper connectors. It has been found, particularly with mirror panels, that the projecting arms can easily be knocked during transit and damage or break the panel because of the leverage they exert. If a suspension arm or guide is damaged, the entire corner connector must be replaced, and care must be taken to obtain a correctly "handed" replacement connector. The guides and suspension arms are located by means of rivets passing through slots. The rivets must permit free sliding movement of the parts without excessive play. It is difficult to obtain adequate control during manufacture of the rivets and the riveting step to ensure a correct fit, resulting in a significant proportion of reject connectors which must be identified and reworked or discarded. If an unduly stiff connector escapes detection and is assembled into a door, the defect may well not come to light until the door is installed and fails to operate properly. If upon installation of a door, it turns out that a connector is damaged or defective a replacement must be obtained and installed, resulting in substantial delay and expense if the required part is not to hand. It also requires some skill to remove and refit a connector without damage to the adjacent components. Whilst I have referred above to the the Kellems patent as a convenient means of setting forth the prior art, it should be understood that similar connectors are already available on the market incorporating advances beyond the Kellems structure. Thus the Kellems patents is directed to a connector which is locked in situ by a spring detent which snaps into an opening in the stile. In practice it is found that the spring detent sometimes malfunctions, since the body of the connector is formed for reasons of economics and workability of a grade of steel which has limited elasticity. Consequently, if the detent is deflected more than usual for any reason, it can become permanently bent and fail to operate properly. Reliable results can be obtained without using the Kellems invention by employing a fixed projection on the bracket and relying upon the elasticity of the stile to provide the desired detenting action. Likewise the guide members to which the Brydoff Pat. No. 744,178 are directed, which are also utilized in the Kellems patent and which have two laterally offset feet, need not be used. I find that by using feet which are one behind the other without lateral offset, the feet may be made wider, they tend to support each other when deflected, and they are both satsifactorily retained in the track and easily removed from it when required.